Euthanasia of livestock is necessary both for livestock processing operations and for farms and other facilities where it is necessary to euthanize sick, injured or compromised animals. There's been significant effort dedicated to developing devices, methods and guidelines or the humane dispatch of livestock.
Captive bolt devices represent one category of tool for use in the euthanasia of livestock. These devices have a housing that supports a moveable bolt that is moved between a retracted and extended position using a variety of actuation mechanisms. The bolts are “captive” because they are not released from the housing. Instead, the bolt is returned to the retracted position after each operation.
Penetrating captive bolt devices are used for stunning animals prior to processing and generally have a long cylindrical bolt that penetrates the skull of an animal to be euthanized. Proper use typically entails locating the device such that the captive bolt penetrates through the skull attempting to disrupt the brain stem and stun the animal into unconsciousness. If the brain is sufficiently damaged during the stun the animal will be unrecoverable and considered euthanatized. Euthanasia by penetrating captive bolt may be aesthetically displeasing.
Non-penetrating captive bolt devices typically have a wide mushroom-shaped head on the captive bolt that does not penetrate the brain of the animal. Generally, such devices are used only to stun the animal into unconsciousness, after which a secondary step, such as exsanguination, is performed to ensure the animal is unrecoverable.